Rollup merge of #106978 - mejrs:mir_build3, r=davidtwco

Migrate mir_build's borrow conflicts

This also changes the error message slightly, for two reasons:

- I'm not a fan of saying "value borrowed, by `x`, here"
- it simplifies the error implementation significantly.

diff --cc compiler/rustc_error_messages/locales/en-US/mir_build.ftl
Simple merge

diff --cc compiler/rustc_mir_build/src/errors.rs
Simple merge

diff --cc compiler/rustc_mir_build/src/thir/pattern/check_match.rs
Simple merge